Pressure operated switrch



April 25, 1950 J. 0. GILL PRESSURE OPERATED SWITCH 2 Sheets-Sheet 3,,

Filed May 14, 1946 Patented Apr. 25, 1950 UNITED STATES PATENT OFFICE 1Claim. 1

This invention relates generally to signaling apparatus and pertainsparticularly to an improved apparatus ior use in connection with mineventilating systems.

The present invention has for its primary object to provide a signalingmechanism which is designed to be used in association with theventilating fan or fans used in association with mine ventilatingsystems for the purpose of designating when the fans are operating atproper speed and for giving an audible warning signal in the event ofthe stoppage of the air circulatin fan or in the event that its speedfalls to a point where proper air movement is not being maintained.

Another object of the invention is to provide signaling mechanismwherein is employed an oscillatable circuit controller which has twopositions, in one of which positions a signal lamp is maintainedenergized during the operation of the ventilating fan at proper speedwhile in the other position such signal lamp is deenergized and abattery operated audible signal is energized to indicate the reductionof the ians speed to a dangerous point.

Still another object of the invention is to provide a safety signalingapparatus of the character stated with the air circulating fan of whichis operatively connected through a suitable speed reduction mechanism, arocking switch which is closed once for each of a predetermined numberof revolutions of the fan to intermittently energize an indicating lightwhereby a visual means is provided for indicating when the fan isrunning at constant speed and also for indicating any slowing up of thespeed prior to the operation of the audible signal.

The invention will be best understood from a consideration of thefollowing detailed description taken in connection with the accompanyingdrawings forming a part of the specification, with the understanding,however, that the invention is not confined to a strict conformity withthe showing of the drawings but may be changed or modified so long assuch changes or modification mark no material departure from the salientfeatures of the invention as expressed in the appended claim.

In the drawings:

Figure 1 illustrates diagrammatically the circuit control units togetherwith the electric circuits associated therewith, forming a part of thepresent invention.

Figure 2 is a view in elevation of the fluid pressure actuated switchcontrolling unit.

Figure 3 is a view in side elevation of the circuit control switchoperated by the speed reduction mechanism.

Figure 4 is a front view of the structure shown in Figure 3.

Figure 5 is a. side view of the fluid pressure operated switchcontrolling unit, portions of the structure being broken away to showdetails of construction.

Referring now more particularly to the drawings the numeral Illgenerally designates a fluid pressure operated unit for controlling theoscillatable switch unit II by means of which certain hereinafterdescribed electric circuits and signal elements are energized underprescribed conditions.

The unit It! comprises a two part housing or a casing in which the partsare designated l2 and between which is secured the flexible diaphragm13.

To the lower section or half of the diaphragm enclosing body isconnected a pipe line 14 which is in communication with the fan chamberor housing, not shown, of the ventilating system in association withwhich the present invention is used. Fluctuations in the air pressurewithin such fan enclosing chamber operate to flex the diaphragm l3 andmove the switch unit I I.

Mounted upon the top of the diaphragm unit I0 is the switch unit II, asshown, and which comprises a platform or plate 15 disposed betweenupstanding bearings IE and pivotally connected therewith by pins l7whereby the plate may be oscillated. At one side of the center ofoscillation for the plate l5, the plate has pivotally connectedtherewith an end of an actuating rod [8 which passes downwardly throughthe top portion [2 of the diaphragm housing and is attached to thediaphragm I3 as indicated at !9. Thus it will be seen that when thediaphragm moves up or down corresponding movement will be given to theplate [5.

If desired the opposite ends of the plate i5 may be fitted with balancearms 2% upon each of which may be shiftably supported the balance weight2|. By properly adjusting the weight upon the arms 2i] the plate l5 maybe delicately balanced if desired so as to react easily to movements ofthe diaphragm.

Supported upon the top of the plate I5 in holders or clips 22 is amercury switch tube 23, in each end of which is fixed a pair ofconductors whereby the mercury switch may control two separate circuits.

As shown in Figure 1 one pair of conductors 24 nected. Also in thecircuit 21 is connected asignal light 29 which is energized when-themercury switch 23 is inclined so as to establish an electricalconnection between the electrodes or terminals 26.

Since the present apparatus is designed to give a warning in the eventthat electrically operated apparatus ceases to function and especiallyif such cessation is due to the failure of the electric current supplyit will be obvious that the signal circuit 25 must be independent ofsuch current supplyv and accordingly this circuit 25lis shown as havingconnected therein a source of electric potential in the form of abattery 39. Also connected in the circuit 25 is a manual switch 3i andan audible signaling element 32 here shown as being in the form of abell. It will be evident,

however, that the-audible signal 32 may comprise a horn, siren or anyother mechanism for creating sound.

Also forming a part of the present signal system is a means fordesignating by the intermittent operation of a signal light, when theventilat- 7 ing system fan is operating at proper speed. For thispurpose there is provided a gear reduction unit which is generallydesignated 33 and which comprises a power input shaft 3:! which isdirectly coupled with a ventilating fan to be rotated thereby, and apower output shaft 35 which, by reason of the gear reduction mechanism,is rotated at a greatly reduced speed from the shaft 34. For example,the reduction rate may be 50 to l or 100 to 1 so that the shaft 35willcbe turnedonce or twice to every 100 revolutions of the ventilatingfan motor.

The shaft 35 has connected therewith the crank 36. and this is connectedby the link 31 with a crank pin 38 which is carried at one side of anoscillatable switch support or cradle 39. The switch support ispivotally mounted between suitable bearings 39 so that as the crank35'rotates rocking movement will be given to the cradle as will bereadily apparent.

Upon the top of the cradle 39 is secured between the clips 4|, themercury switch tube 42 into one end of which extends electrodes 43 whichareconnected in the signaling circuit 44. Also connected in the circuit44 is a signal lamp 45 and the circuit is supplied from any suitablesource by the necessary electric power which is connected with the leads46.

It will be readily seen from the foregoing that the signaling circuit 44will be intermittently energized by the oscillation of the mercur switch42 and accordingly it will be readily apparent to anyone observing thesignal light 45 when the fan operating motor is performing properly. Inthe event of any difficulty which might make the operation of theventilating fan motor erratic the signal light will fail to light atproperly timed intervals or will fail to light at all if the fan motorhas ceased functioning. In the latter event the pressure diaphragm Itwill b afiected and the audible signal will be sounded to give a warningif the condition of the fan has not been noted visually.

From the foregoing it will be readily apparent that when the presentapparatus is installed in a mine ventilating system and properlyconnected with the'electrically operated units thereof adequate warningwill b given in the event that the'air circulating apparatus fails forany reason to function properly and accordingly the necessary steps canbe taken immediately to remedy the situation and thus avoid thepossibility of some dangerous conditions developing.

I claim:

A fluid actuated diaphragm controlled electric circuit controlcomprising a housing having upper and lower portions between which afree moving 1 diaphragm is secured, the top of the housing being. openand a fluid pipe opening into the housing beneath the diaphragm, spacedupright supports mounted upon the upper portion of the housing, theopening in the housing top being between said supports, a platformdisposed between the supports, pivot means connecting opposite sideedges of the platform with the supports whereby the platform isoscillatably carried by the supports, a rod secured at one end to thediaphragm and extending upwardly through said opening and having pivotalconnection at its other end with the platform, the connection betweenthe rod and the platform being to one side of the pivot support for theplatform whereby the movements of the diaphragm will effect oscillationof the platform, a pair of. spaced clip members carried upon theplatform, a mercury switch secured at its ends between the clip membersto be maintained above and substantially in parallel relation with thetop of the platform, and elements supported upon two, opposite ends ofthe platform for regulating the balance thereof, comprising a long,threaded arm extending longitudinally from each of such ends and abalance weight threaded on each arm.

JOHN O. GILL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 872,039 Adams Nov. 26, 1907 11,372,500 Gamille Mar. 22, 1921 1,776,297 Sanderson Sept. 23, 19302,069,953 Hopkins Feb. 9, 1937 2,139,411 Jennings Dec. 6, 1938 2,302,562Loepsinger Nov. 17, 1942 FOREIGN PATENTS Number Country Date 492,973Great Britain Sept. 30, 1938

